Travel advice

I am living in Jakarta now. After going home for Christmas I am hoping to make my first trip to Vietnam.  I'd like to fly from the US to Hanoi and travel by land to Ho Chi Minh, then fly back to Jakarta.  Alternately I could start into Chi Minh and travel to Hanoi and then out.
I've never been to Vietnam before. I'm hoping to spend 7-10 days.  Is this reasonable? What are costs like?  Will bus/train transport be easy heading from one city to another with stops between? Must see sights?  Good hostels?
Thanks!

Vietnam is a very long & narrow country and HCM to Hanoi is about 2,000 km if I'm not wrong.  The roads aren't exactly freeways, and you don't want to spend all your 7-10 days on the road.  Best if you fly bewteen these 2 main cities and just spend about 3 days in each.

HCM is a little more modern than Hanoi but still far from Jakarta in my humble opinion.  But Hanoi is more charming.  Climate-wise, HCM is quite like Jakarta and Hanoi is quite a bit cooler.  Food & cabs are relatively cheap.

Check out agoda or asiarooms for hostels & reviews.

Good luck & have fun.

I suggest you a program as below:
Day 1: Hanoi -Arrival - City tour (if time permits)
Day 2: Hanoi - Halong Bay. Overnight on board (recommended)
Day 3: Halong Bay - Hanoi.
Day 4: Hanoi - Saigon (by flight, it takes 2 hours) - City tour
Day 5: Mekong Delta 1 day
Day 6: Cu Chi Tunnels - Cao Dai temple 1 day
Day 7: Free for shopping then departure.

This is program for 7 days, If you have more time,you can visit some more beauty spots in Hanoi and Saigon.
You should book tours at travel agencies there. You will travel with group, so the tour price is reasonable.Cost for 7 days as I mentioned above is about 600 USD.

Have a good trip!